AWS Microsoft AD is a highly available, managed Active Directory built on actual Windows Server 2012 R2 in the AWS Cloud. With AWS Microsoft AD, you do not have to synchronize identities from your on-premises Active Directory domain to the AWS Cloud. AWS provides automated software updates, security patching, and failover as part of the service.

Adding domain controllers increases the redundancy, which results in even greater resilience and higher availability. Adding domain controllers also improves the performance of your applications by enabling directory clients to load-balance their requests across a larger number of domain controllers. For example, AWS Microsoft AD enables you to use large fleets of Amazon EC2 instances to run your .NET applications that perform frequent user attribute lookups.